Following the aforementioned approach, face landmarks are detected on the visible spectrum using [1]}. A bounding box is then constructed from the landmarks to have a tight crop of the face. The bounding box of the visible spectrum is then projected to the corresponding co-ordinate system of the other cameras to extract approximately aligned faces on different modalities. Each channel is then scaled to the range \([0, 1]\)  by dividing the bit depth of the camera and then resized to \(160\times 160\)  pixels. In our experiments, we use the visible range information as input to our algorithm. A future direction includes considering beyond the visible information to perform PAD.
